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Lim JH, Kim JY, Kang DW, Choi KH, Lee SJ, Im SH, Park BJ. Heterogeneous Capillary Interactions of Interface-Trapped Ellipsoid Particles Using the Trap-Release Method. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:384-394. [PMID: 29232143 DOI: 10.1021/acs.langmuir.7b03882] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Heterogeneous capillary interactions between ellipsoid particles at the oil-water interface were measured via optical laser tweezers. Two trapped particles were aligned in either tip-to-tip (tt) or side-to-side (ss) configurations via the double-trap method and were released from the optical traps, leading to particle-particle attractions due to the capillary forces caused by quadrupolar interface deformation. On the basis of image analysis and calculations of the Stokes drag force, the capillary interactions between two ellipsoid particles with the same aspect ratio (E) were found to vary with the particle pairs that were measured, indicating that the interactions were nondeterministic or heterogeneous. Heterogeneous capillary interactions could be attributed to undulation of the interface meniscus due to chemical and/or geometric particle heterogeneity. The power law exponent for the capillary interaction Ucap ≈ r-β was found to be β ≈ 4 and was independent of the aspect ratio and particle configuration in long-range separations. Additionally, with regard to the tt configuration, the magnitude of the capillary force proportionally increased with the E value (E > 1) when two ellipsoid particles approached each other in the tt configuration.
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Lee M, Park JT, Yang JH, Kim D, Je IG, Lee YS, Jeong J, Song DK, Park S, Lee HS, Kim YM, Lee SW, Kang DW, Lee HY, Kim JY, Lee S, Baek NS, Kang JH. Abstract A106: Development of IDX-1197, a novel, selective, and highly potent PARP inhibitor. Mol Cancer Ther 2018. [DOI: 10.1158/1535-7163.targ-17-a106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: PARP inhibitors have demonstrated clinically meaningful increase in progression-free survival as a single agent in women with recurrent ovarian cancer following a response to platinum-based chemotherapy. However, there still needs more improvement in efficacy because PARP inhibitors have comparatively low efficacy in non-germline BRCA-mutated patients. We aimed to develop a novel PAPR inhibitor that may have potent antitumor efficacy against the non-germline BRCA-mutated patients in addition to the germline BRCA-mutated patients. Here, we describe a novel selective PARP inhibitor IDX-1197. Materials and Methods: We conducted in vitro assays to evaluate IDX-1197 as a PARP inhibitor using PARP enzyme assay and PARP-catalytic inhibition assay in Hela cells. We evaluated in vivo efficacy of IDX-1197 against ovarian and breast tumor growth using patient-derived xenograft models. To investigate PARP inhibition in tumors, tumor PAR levels were measured by ELISA in the PDX models. Results: In enzyme assay, IDX-1197 potently inhibited PARP1 and PARP2 activities with IC50 values of 1.4 nM and 1.0 nM, respectively. By contrast, IDX-1197 was not sensitive to PARP5A (Tankyrase-1), which belongs to the PARP family (IC50>10 μM). In DNA damage-induced Hela cells, IDX-1197 significantly inhibited PARP1-mediated PAR expression (EC50 = 0.5 nM). In the germline BRCA1-mutated ovarian cancer PDX model, oral administration of IDX-1197 exhibited significant PAR inhibition (>90%) in tumor tissues until 24 hr post dose. IDX-1197 also dose-dependently led to potent tumor growth inhibition compared to Olaparib treatment group. Furthermore, IDX-1197 showed improved antitumor activity against breast cancer PDX models, which included both germline BRCA-mutated and non-germline BRCA-mutated models. In these models, IDX-1197 exhibited greater tumor growth inhibition compared with olaparib and/or niraparib. Conclusions: IDX-1197 is a highly potent and selective inhibitor of PARP1/2 with significant in vitro and in vivo activities in multiple cancer models. These preclinical data demonstrate the efficacy of IDX-1197, which has the potential for a best-in-class profile, in non-germline BRCA-mutated patients as well as BRCA-mutated patients. Based on these findings, IDX-1197 has entered clinical phase 1 trial in Korea. Funded by National OncoVenture.
Citation Format: Myongjae Lee, Joon-Tae Park, Ji-hun Yang, Dohee Kim, In-Gyu Je, Yoon Suk Lee, Jinah Jeong, Dong Keun Song, Soobong Park, Hong-Sub Lee, Yong-Man Kim, Shin-Wha Lee, Dong Woo Kang, Ha-Young Lee, Jung Yong Kim, Sungsook Lee, Nam Seok Baek, Jae-Hoon Kang. Development of IDX-1197, a novel, selective, and highly potent PARP inhibitor [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A106.
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Kwak HD, Ju JK, Kang DW, Baek SJ, Kwak JM, Kim J, Kim SH. Outcomes according to body mass index following laparoscopic surgery in patients with colorectal cancer. J Minim Access Surg 2018; 14:134-139. [PMID: 28928331 PMCID: PMC5869973 DOI: 10.4103/jmas.jmas_68_17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Purpose: Body mass index (BMI) may not be appropriate for different populations. Therefore, the World Health Organization (WHO) suggested 25 kg/m2 as a measure of obesity for Asian populations. The purpose of this report was to compare the oncologic outcomes of laparoscopic colorectal resection with BMI classified from the WHO Asia-Pacific perspective. Patients and Methods: All patients underwent laparoscopic colorectal resection from September 2006 to March 2015 at a tertiary referral hospital. A total of 2408 patients were included and classified into four groups: underweight (n = 112, BMI <18.5 kg/m2), normal (n = 886, 18.5–22.9 kg/m2), pre-obese (n = 655, 23–24.9 kg/m2) and obese (n = 755, >25 kg/m2). Perioperative parameters and oncologic outcomes were analysed amongst groups. Results: Conversion rate was the highest in the underweight group (2.7%, P < 0.001), whereas the obese group had the fewest harvested lymph nodes (21.7, P < 0.001). Comparing oncologic outcomes except Stage IV, the underweight group was lowest for overall (P = 0.007) and cancer-specific survival (P = 0.002). The underweight group had the lowest proportion of national health insurance but the highest rate of medical care (P = 0.012). Conclusion: The obese group had the fewest harvested lymph nodes, whereas the underweight group had the highest estimated blood loss, conversion rate to open approaches and the poorest overall and cancer-specific survivals.
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Joo SH, Yun SH, Kang DW, Hahn CT, Lim HK, Lee CU. Body Mass Index in Mild Cognitive Impairment According to Age, Sex, Cognitive Intervention, and Hypertension and Risk of Progression to Alzheimer's Disease. Front Psychiatry 2018; 9:142. [PMID: 29719518 PMCID: PMC5913709 DOI: 10.3389/fpsyt.2018.00142] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 04/03/2018] [Indexed: 12/20/2022] Open
Abstract
Introduction: Mild cognitive impairment (MCI) is a prodromal stage of dementia. The association of body mass index (BMI) and progression to Alzheimer's disease (AD) in MCI subjects according to age, sex, and cognitive intervention remains unknown. We investigated the relationship between BMI and the risk of progression to AD in subjects with MCI, as well as the effect of BMI on progression to AD depending on age, sex, cognitive intervention, and chronic diseases. Methods: Three hundred and eighty-eight MCI subjects were followed for 36.3 ± 18.4 months, prospectively. They underwent neuropsychological testing more than twice during the follow-up period. The MCI subjects were categorized into underweight, normal weight, overweight, and obese subgroups. The associations between baseline BMI and progression to AD over the follow-up period were estimated using Cox proportional hazard regression models. Data were analyzed after stratification by age, sex, cognitive intervention, and chronic diseases. Results: After adjustment for the covariates, the underweight MCI group had a higher risk of progression to AD [hazard ratio (HR): 2.38, 95% confidence interval (CI): 1.17-4.82] relative to the normal weight group. After stratifying by age, sex, cognitive intervention, and chronic diseases, this effect remained significant among females (HR: 3.15, 95% CI: 1.40-7.10), the older elderly ≥75 years old (HR: 3.52, 95% CI: 1.42-8.72), the non-intervention group (HR: 3.06, 95%CI: 1.18-7.91), and the hypertensive group (HR: 4.71, 95% CI: 1.17-18.99). Conclusion: These data indicate that underweight could be a useful marker for identifying individuals at increased risk for AD in MCI subjects. This association is even stronger in females, older elderly subjects, the non-cognitive intervention group, and the hypertensive group.
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Kang DW, Lim HK, Joo SH, Lee NR, Lee CU. The association between hippocampal subfield volumes and education in cognitively normal older adults and amnestic mild cognitive impairment patients. Neuropsychiatr Dis Treat 2018; 14:143-152. [PMID: 29379287 PMCID: PMC5757976 DOI: 10.2147/ndt.s151659] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
OBJECTIVE Previous research has indicated that there are potential associations between education and total hippocampal volume in the trajectory of Alzheimer's disease (AD). However, the correlation between education and hippocampal subfield volumes in the progression of AD has yet to be understood. This study examined the relationship between education, which is a standard proxy for cognitive reserve, and hippocampal subfield volumes in healthy and amnestic mild cognitive impairment (aMCI) groups. SUBJECTS AND METHODS Thirty-eight subjects with aMCI and 39 healthy control subjects underwent 3 T magnetic resonance imaging, and hippocampal subfield volumes were measured by automated segmentation. Multiple linear regression analysis was used to determine the association between education and hippocampal subfield volumes. RESULTS Education had a significant negative correlation with the left parasubiculum, presubiculum, and subiculum volumes in the aMCI group. In addition, multiple subfield volumes including left parasubiculum, left/right presubiculum, left cornus ammonis (CA)3, and left CA4 showed a significant correlation with the neuropsychological test scores in the control group and aMCI group. CONCLUSION These findings contribute to a better understanding of the association between education, hippocampal subfield volumes, and amnestic cognitive functions in the early phase of AD.
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Kang DW, Lee M, Kim KH, Xia M, Im SH, Park BJ. Electrostatic interactions between particles through heterogeneous fluid phases. SOFT MATTER 2017; 13:6647-6658. [PMID: 28926066 DOI: 10.1039/c7sm01309d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We investigated the electrostatic interactions between particles acting through heterogeneous fluid phases. An oil lens system floating on the surface of water was used to trap particles at different fluid-fluid interfaces. The inner particles are located at the centrosymmetrically curved oil-water interface inside the oil lens while satellite particles are located at the curved air-water interface, separated by a particular distance from the triple phase boundary. The satellite particles are likely to be captured in an energy minimum state due to electrostatic repulsions by the inner particles balanced with the gravity-induced potential energy. As the size of the oil lens decreases upon evaporation, the satellite particles escape from the gravitational confinement at a critical moment. The self-potential values of the inner particles and the satellite particles were calculated by employing an energy balance and the experimentally obtained geometric parameter values. It was found that the self-potential values of the inner particles decrease as oil evaporates over time and that the magnitude of the self-potential of the satellite particles is a hundred times larger than that of the inner particles. These results demonstrate significant effects of the thickness and shape of the nonpolar superphase on the electrostatic interactions between the particles trapped at different fluid-fluid interfaces.
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Kang DW, Lee BH, Suh YA, Choi YS, Jang SJ, Kim YM, Choi KY, Min DS. Phospholipase D1 Inhibition Linked to Upregulation of ICAT Blocks Colorectal Cancer Growth Hyperactivated by Wnt/β-Catenin and PI3K/Akt Signaling. Clin Cancer Res 2017; 23:7340-7350. [DOI: 10.1158/1078-0432.ccr-17-0749] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 07/19/2017] [Accepted: 09/18/2017] [Indexed: 11/16/2022]
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Kang DW, Lim JH, Park BJ. Heterogeneous interface adsorption of colloidal particles. SOFT MATTER 2017; 13:6234-6242. [PMID: 28805212 DOI: 10.1039/c7sm00618g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The heterogeneous adsorption behaviors of charged colloidal particles to oil-water interfaces were quantitatively and statistically investigated. Using optical laser tweezers, the particles in a sessile water drop formed in an oil phase were laterally translated toward the slope of the oil-water interface and their attachment to the interface was attempted. The adsorption probability was found to logarithmically decrease as the ionic strength decreased and to depend on the holding time during which an optically trapped particle was held at the position closest to the interface. Non-unity of the adsorption probability at particular salt concentrations and the holding time dependence offer an important clue that the particle adsorption to the interface is not deterministic but stochastic. The stochastic adsorption process can be attributed to the surface heterogeneity of colloidal particles that consequently leads to changes in the electrostatic interactions between the particles and the interface. We also demonstrated that the salt dependence on the adsorption properties of the particles, as measured by optical laser tweezers, was consistent with their bulk behaviors with regard to the stability of particle-stabilized emulsions. Furthermore, we revealed the gravity-induced spontaneous adsorption of the particles to the interface under conditions of sufficiently strong ionic strength.
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Kwak HD, Kim J, Kang DW, Baek SJ, Kwak JM, Kim SH. Hartmann's reversal: a comparative study between laparoscopic and open approaches. ANZ J Surg 2017; 88:450-454. [PMID: 28730630 DOI: 10.1111/ans.13979] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Revised: 02/13/2017] [Accepted: 02/27/2017] [Indexed: 12/16/2022]
Abstract
BACKGROUND A reversal of Hartmann's procedure can be performed using either a laparoscopic or open approach. However, laparoscopic reversal (LR) of Hartmann's procedure is challenging. This study was designed to compare the results between open and laparoscopic approaches. METHODS This was a retrospective study of prospectively collected data. We analysed 29 patients who received Hartmann's reversal at Korea University Anam Hospital between April 2007 and September 2014. All patients underwent either LR (n = 17) or open reversal (OR, n = 12). RESULTS Patient characteristics were similar between the LR and OR groups. There was also no difference in mean operation time (212.5 versus 251.8 min), diversion ileostomy, length of hospital stay, postoperative analgesic days, time to diet resumption (3.9 versus 6.2 days) or complication rate. Although the time to resuming a solid diet was not different between the two groups (P = 0.053), bowel movement occurred faster in LR patients (LR versus OR, 1.8 versus 2.8 days, P = 0.020). Patients in the LR group also had less blood loss during surgery (114.1 versus 594.2 mL, P = 0.026). There were no mortalities in this study. CONCLUSION LR of Hartmann's procedure resulted in faster bowel function recovery than the open method. Laparoscopic approaches are feasible even for patients who received an open Hartmann's procedure.
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Lee CU, Kang DW, Lim HK. [P3–369]: DIAGNOSTIC VALIDITY OF AN AUTOMATED PROBABILISTIC TRACTOGRAPHY IN AMNESTIC MILD COGNITIVE IMPAIRMENT. Alzheimers Dement 2017. [DOI: 10.1016/j.jalz.2017.06.1585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Kang DW, Lee CU. [P4–233]: DIFFERENTIAL FUNCTIONAL CONNECTIVITY OF POSTERIOR CINGULATE CORTEX IN THE DECLINE OF COGNITIVE RESERVE BETWEEN AMNESTIC MILD COGNITIVE IMPAIRMENT AND MILD ALZHEIMER's DISEASE. Alzheimers Dement 2017. [DOI: 10.1016/j.jalz.2017.06.2101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Kang DW, Lee CU, Lim HK. Role of Sleep Disturbance in the Trajectory of Alzheimer's Disease. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE 2017; 15:89-99. [PMID: 28449556 PMCID: PMC5426492 DOI: 10.9758/cpn.2017.15.2.89] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 10/16/2016] [Accepted: 10/17/2016] [Indexed: 12/21/2022]
Abstract
Sleep disturbances such as insomnia, hypersomnia, and circadian rhythm disturbance are common in normal elderly and Alzheimer’s disease (AD) patients. To date, special attention has been paid to sleep disturbance in the clinical course of AD insofar as the interaction of sleep disturbance with the pathogenesis of AD may impact the clinical course and cognitive function of AD patients. This review covers the bidirectional relationship between sleep disturbance and AD pathogenesis; the associations between sleep disturbance and AD-specific neurotransmitters, brain structure, and aspects of sleep disturbance in each phase of AD; and the effects of sleep disturbance on the cognitive functions of patients in each phase of AD. We consider several factors required to exactly interpret the results and suggest a direction for future studies on the role of sleep disturbance in AD.
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Lim JH, Kang DW, Park BJ. Analytical calculations of optical trapping forces for drag calibration: Effects of mismatch between beam focus and particle center. Macromol Res 2017. [DOI: 10.1007/s13233-017-5027-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Kang DW, Kwak HD, Sung NS, Yang IS, Baek SJ, Kwak JM, Kim J, Kim SH. Oncologic outcomes in rectal cancer patients with a ≤1-cm distal resection margin. Int J Colorectal Dis 2017; 32:325-332. [PMID: 27900522 DOI: 10.1007/s00384-016-2708-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/18/2016] [Indexed: 02/04/2023]
Abstract
PURPOSE Recently, common application of sphincter-saving resection in rectal cancer has led to acceptance of a 1-cm distal resection margin (DRM). The aim of this study was to evaluate oncologic outcomes of a DRM ≤1 cm in sphincter-saving resection for rectal cancer. The outcomes of a DRM ≤0.5 cm was also evaluated. METHODS We reviewed prospectively collected data from 415 patients who underwent sphincter-saving resection for mid and low rectal cancer between September 2006 and December 2012 at Korea University Anam Hospital. Patients were divided into two groups according to DRM measured in a formalin fixed specimen: ≤1 cm (n = 132) and >1 cm (n = 283). The DRM ≤1 cm group was divided into two subgroups: ≤0.5 cm (n = 45) and >0.5, ≤1 cm (n = 87). RESULTS Median follow-up periods were 47.2 months. The 5-year local recurrence rate was 8.8% in the DRM ≤1 cm group and 8.5% in the DRM >1 cm group (p = 0.630). The 5-year disease-free survival rate was 75.1 and 76.3% (p = 0.895), and the 5-year overall survival rate was 82.6 and 85.9% (p = 0.401), respectively. In subanalysis of the DRM ≤1 cm group, there was also no significant difference in the local recurrence and survival. CONCLUSIONS There was no significant difference in local recurrence and survival based on DRM length. We found that DRM length less than 1 cm was not a prognostic factor for local recurrence or survival.
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Kang DW, Yang ES, Noh YN, Hwang WC, Jo SY, Suh YA, Park WS, Choi KY, Min DS. MicroRNA-320a and microRNA-4496 attenuate Helicobacter pylori cytotoxin-associated gene A (CagA)-induced cancer-initiating potential and chemoresistance by targeting β-catenin and ATP-binding cassette, subfamily G, member 2. J Pathol 2017; 241:614-625. [PMID: 28008607 DOI: 10.1002/path.4866] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 12/01/2016] [Accepted: 12/15/2016] [Indexed: 01/04/2023]
Abstract
Infection with Helicobacter pylori is closely linked to an increased risk of gastric cancer. Although cytotoxin-associated gene A (CagA), a major virulence factor of H. pylori, is known to be a causal factor for gastric carcinogenesis, the molecular link between CagA and gastric cancer-initiating cell (CIC)-like properties remains elusive. Here, we demonstrate that CagA is required for increased expression of β-catenin and its target CIC markers via downregulation of microRNA (miR)-320a and miR-4496. CagA promoted gastric CIC properties and was responsible for chemoresistance. miR-320a and miR-4496 attenuated the in vitro self-renewal and tumour-initiating capacity of CagA-expressing CICs by targeting β-catenin. Moreover, miR-320a and miR-4496 decreased CagA-induced chemoresistance by targeting ATP-binding cassette, subfamily G, member 2 (ABCG2) at the transcriptional and post-transcriptional levels, respectively. Combination therapy with 5-fluorouracil and miR-320a/miR-4496 suppressed gastric tumourigenesis and metastatic potential in an orthotopic mouse model, probably via suppression of CagA-induced CIC properties and chemoresistance. Our results provide novel evidence that CIC properties, chemoresistance and tumourigenesis associated with H. pylori are linked to CagA-induced upregulation of β-catenin and ABCG2. These data provide novel insights into the molecular mechanisms of CagA-induced carcinogenisis and the therapeutic potential of of miR-320a and miR-4496. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Kang DW, Lee SW, Hwang WC, Lee BH, Choi YS, Suh YA, Choi KY, Min DS. Phospholipase D1 Acts through Akt/TopBP1 and RB1 to Regulate the E2F1-Dependent Apoptotic Program in Cancer Cells. Cancer Res 2016; 77:142-152. [PMID: 27793841 DOI: 10.1158/0008-5472.can-15-3032] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 10/10/2016] [Accepted: 10/23/2016] [Indexed: 01/11/2023]
Abstract
The RB1/E2F1 signaling pathway is frequently deregulated in colorectal cancer and has been suggested to intersect with Wnt/β-catenin and PI3K/Akt pathways, but molecular evidence for this link is lacking. In this study, we demonstrate that phospholipase D1 (PLD1), a transcriptional target of β-catenin/TCF4, orchestrates functional interactions between these pathways during intestinal tumor development. Overexpression of PLD1 in intestinal epithelial cells protected cells from apoptosis induced by PLD1 ablation in the Apcmin/+ mouse model of intestinal tumorigenesis. Mechanistic investigations revealed that genetic and pharmacologic targeting of PLD1 promote the E2F1-dependent apoptotic program via both miR-192/4465-mediated downregulation of RB1 and inhibition of Akt-TopBP1 pathways. Moreover, the miRNA-RB1 axis and Akt pathway also contributed to the PLD1-mediated self-renewal capacity of colon cancer-initiating cells. Finally, PLD1-driven E2F1 target gene expression positively correlated with tumor stage in patients with colorectal cancer. Overall, our findings suggest that PLD1 mediates cross-talk between multiple major signaling pathways to promote the survival and malignancy of colon cancer cells and may therefore represent an ideal signaling node for therapeutic targeting. Cancer Res; 77(1); 142-52. ©2016 AACR.
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Kang DW, Ko W, Lee B, Park BJ. Effect of Geometric and Chemical Anisotropy of Janus Ellipsoids on Janus Boundary Mismatch at the Fluid-Fluid Interface. MATERIALS 2016; 9:ma9080664. [PMID: 28773787 PMCID: PMC5509275 DOI: 10.3390/ma9080664] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 07/20/2016] [Accepted: 08/04/2016] [Indexed: 11/16/2022]
Abstract
We investigated the geometric and chemical factors of nonspherical Janus particles (i.e., Janus ellipsoids) with regard to the pinning and unpinning behaviors of the Janus boundary at the oil-water interface using attachment energy numerical calculations. The geometric factors were characterized by aspect ratio (AR) and location of the Janus boundary (α) separating the polar and apolar regions of the particle. The chemical factor indicated the supplementary wettability (β) of the two sides of the particle with identical deviations of apolarity and polarity from neutral wetting. These two factors competed with each other to determine particle configurations at the interface. In general, the critical value of β (βc) required to preserve the pinned configuration was inversely proportional to the values of α and AR. From the numerical calculations, the empirical relationship of the parameter values of Janus ellipsoids was found; that is, λ = Δ β c / Δ α ≈ 0.61 A R - 1.61 . Particularly for the Janus ellipsoids with AR > 1, the βc value is consistent with the boundary between the tilted only and the tilted equilibrium/upright metastable region in their configuration phase diagram. We believe that this work performed at the single particle level offers a fundamental understanding of the manipulation of interparticle interactions and control of the rheological properties of particle-laden interfaces when particles are used as solid surfactants.
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Kang DW, Noh YN, Hwang WC, Choi KY, Min DS. Rebamipide attenuates Helicobacter pylori CagA-induced self-renewal capacity via modulation of β-catenin signaling axis in gastric cancer-initiating cells. Biochem Pharmacol 2016; 113:36-44. [PMID: 27265143 DOI: 10.1016/j.bcp.2016.06.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Accepted: 06/01/2016] [Indexed: 02/07/2023]
Abstract
Rebamipide, a mucosal-protective agent, is used clinically for treatment of gastritis and peptic ulcers induced by Helicobacter pylori (H. pylori) which is associated with increased risk of gastric cancer. Although rebamipide is known to inhibit the growth of gastric cancer cells, the action mechanisms of rebamipide in gastric carcinogenesis remains elusive. Here, we show that rebamipide suppresses H. pylori CagA-induced β-catenin and its target cancer-initiating cells (C-IC) marker gene expression via upregulation of miRNA-320a and -4496. Rebamipide attenuated in vitro self-renewal capacity of H. pylori CagA-infected gastric C-IC via modulation of miRNA-320a/-4496-β-catenin signaling axis. Moreover, rebamipide enhanced sensitivity to chemotherapeutic drugs in CagA-expressed gastric C-IC. Furthermore, rebamipide suppressed tumor-initiating capacity of gastric C-IC, probably via suppression of CagA-induced C-IC properties. These data provide novel insights for the efficacy of rebamipide as a chemoprotective drug against H. pylori CagA-induced carcinogenic potential.
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Ji WB, Kwak JM, Kang DW, Kwak HD, Um JW, Lee SI, Min BW, Sung NS, Kim J, Kim SH. Clinical benefits and oncologic equivalence of self-expandable metallic stent insertion for right-sided malignant colonic obstruction. Surg Endosc 2016; 31:153-158. [PMID: 27194253 DOI: 10.1007/s00464-016-4946-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 04/15/2016] [Indexed: 12/13/2022]
Abstract
BACKGROUND The efficacy of stenting for right-sided malignant colonic obstruction is unknown. This study aimed to evaluate the safety, feasibility, and clinical benefits of self-expandable metallic stent insertion for right-sided malignant colonic obstruction. METHODS Clinical data from patients who underwent right hemicolectomy for right colon cancer from January 2006 to July 2014 at three Korea University hospitals were retrospectively reviewed. A total of 39 patients who developed malignant obstruction in the right-sided colon were identified, and their data were analyzed. RESULTS Stent insertion was attempted in 16 patients, and initial technical success was achieved in 14 patients (87.5 %). No stent-related immediate complications were reported. Complete relief from obstruction was achieved in all 14 patients. Twenty-five patients, including two patients who failed stenting, underwent emergency surgery. In the stent group, 93 % (13/14) of patients underwent elective laparoscopic surgery, and only one surgery was converted to an open procedure. All patients in the emergency group underwent emergency surgery within 24 h of admission. In the emergency group, only 12 % (3/25) of patients underwent laparoscopic surgery, with one surgery converted to an open procedure. All patients in both groups underwent either laparoscopy-assisted or open right/extended right hemicolectomy with primary anastomoses as the first operation. The operative times, retrieved lymph nodes, and pathologic stage did not differ between the two groups. Postoperative hospital stay (9.4 ± 3.4 days in the stent group vs. 12.4 ± 5.9 in the emergency group, p = 0.089) and time to resume oral food intake (3.2 ± 2.1 days in the stent group vs. 5.7 ± 3.4 in the emergency group, p = 0.019) were shorter in the stent group. And there were no significant differences in disease-free survival and overall survival between the two groups. CONCLUSIONS Stent insertion appears to be safe and feasible in patients with right-sided colonic malignant obstruction. It facilitates minimally invasive surgery and may result in better short-term surgical outcomes.
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Kim TW, Kim HJ, Kang DW, Kwak HJ, Hong SC. Four Narcolepsy Cases after H1N1 Infection or Vaccination. SLEEP MEDICINE RESEARCH 2015. [DOI: 10.17241/smr.2015.6.1.38] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Kang DW, Choi CY, Cho YH, Tian H, Di Paolo G, Choi KY, Min DS. Targeting phospholipase D1 attenuates intestinal tumorigenesis by controlling β-catenin signaling in cancer-initiating cells. ACTA ACUST UNITED AC 2015; 212:1219-37. [PMID: 26122663 PMCID: PMC4516794 DOI: 10.1084/jem.20141254] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 05/11/2015] [Indexed: 12/20/2022]
Abstract
Kang et al. show that genetic or pharmacological inactivation of the enzyme phospholipase D1 (PLD1) disrupts colitis-associated intestinal tumorigenesis by suppressing the self-renewal capacity of colon cancer stem cells. Expression of the Wnt target gene phospholipase D1 (PLD1) is up-regulated in various carcinomas, including colorectal cancer (CRC). However, the mechanistic significance of its elevated expression in intestinal tumorigenesis remains unknown. In this study, we show that genetic and pharmacological targeting of PLD1 disrupts spontaneous and colitis-associated intestinal tumorigenesis in ApcMin/+ and azoxymethane/dextran sodium sulfate mice models. Intestinal epithelial cell–specific PLD1 overexpression in ApcMin/+ mice accelerated tumorigenesis with increased proliferation and nuclear β-catenin levels compared with ApcMin/+ mice. Moreover, PLD1 inactivation suppressed the self-renewal capacity of colon cancer–initiating cells (CC-ICs) by decreasing expression of β-catenin via E2F1-induced microRNA (miR)-4496 up-regulation. Ultimately, low expression of PLD1 coupled with a low level of CC-IC markers was predictive of a good prognosis in CRC patients, suggesting in vivo relevance. Collectively, our data reveal that PLD1 has a crucial role in intestinal tumorigenesis via its modulation of the E2F1–miR-4496–β-catenin signaling pathway. Modulation of PLD1 expression and activity represents a promising therapeutic strategy for the treatment of intestinal tumorigenesis.
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Kang DW, Choi KY, Min DS. Functional regulation of phospholipase D expression in cancer and inflammation. J Biol Chem 2014; 289:22575-22582. [PMID: 24990948 DOI: 10.1074/jbc.r114.569822] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Phospholipase D (PLD) regulates downstream effectors by generating phosphatidic acid. Growing links of dysregulation of PLD to human disease have spurred interest in therapeutics that target its function. Aberrant PLD expression has been identified in multiple facets of complex pathological states, including cancer and inflammatory diseases. Thus, it is important to understand how the signaling network of PLD expression is regulated and contributes to progression of these diseases. Interestingly, small molecule PLD inhibitors can suppress PLD expression as well as enzymatic activity of PLD and have been shown to be effective in pathological mice models, suggesting the potential for use of PLD inhibitors as therapeutics against cancer and inflammation. Here, we summarize recent scientific developments regarding the regulation of PLD expression and its role in cancer and inflammatory processes.
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Kim HY, Yang DH, Shin SW, Kim MY, Yoon JH, Kim S, Park HC, Kang DW, Min D, Hur MW, Choi KY. CXXC5 is a transcriptional activator of Flk-1 and mediates bone morphogenic protein-induced endothelial cell differentiation and vessel formation. FASEB J 2013; 28:615-26. [PMID: 24136587 DOI: 10.1096/fj.13-236216] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
CXXC5 is a member of a small subset of proteins containing CXXC-type zinc-finger domain. Here, we show that CXXC5 is a transcription factor activating Flk-1, a receptor for vascular endothelial growth factor. CXXC5 and Flk-1 were accumulated in nucli and membrane of mouse embryonic stem cells (mESCs), respectively, during their endothelial differentiation. CXXC5 overexpression induced Flk-1 transcription in both endothelium-differentiated mESCs and human umbilical vein endothelial cells (HUVECs). In vitro DNA binding assay showed direct interaction of CXXC5 on the Flk-1 promoter region, and mutation on its DNA-binding motif abolished transcriptional activity. We showed that bone morphorgenetic protein 4 (BMP4) induced CXXC5 transcription in the cells, and inhibitors of BMP signaling suppressed the CXXC5 induction and the consequent Flk-1 induction by BMP4 treatment. CXXC5 knockdown resulted in suppression of BMP4-induced stress fiber formation (56.8 ± 1.3% decrease, P<0.05) and migration (54.6 ± 1.9% decrease, P<0.05) in HUVECs. The in vivo roles of CXXC5 in BMP-signaling-specific vascular development and angiogenesis were shown by specific defect of caudal vein plex vessel formation (57.9 ± 11.8% decrease, P<0.05) in cxxc5 morpholino-injected zebrafish embryos and by suppression of BMP4-induced angiogenesis in subcutaneously injected Matrigel plugs in CXXC5(-/-) mice. Overall, CXXC5 is a transcriptional activator for Flk-1, mediating BMP signaling for differentiation and migration of endothelial cell and vessel formation.
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Park MH, Kang DW, Jung Y, Choi KY, Min DS. Caffeic acid phenethyl ester downregulates phospholipase D1 via direct binding and inhibition of NFκB transactivation. Biochem Biophys Res Commun 2013; 442:1-7. [PMID: 24103753 DOI: 10.1016/j.bbrc.2013.09.105] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 09/20/2013] [Indexed: 11/26/2022]
Abstract
Upregulation of phospholipase D (PLD) is functionally linked with oncogenic signals and tumorigenesis. Caffeic acid phenethyl ester (CAPE) is an active compound of propolis extract that exhibits anti-proliferative, anti-inflammatory, anti-oxidant, and antineoplastic properties. In this study, we demonstrated that CAPE suppressed the expression of PLD1 at the transcriptional level via inhibition of binding of NFκB to PLD1 promoter. Moreover, CAPE, but not its analogs, bound to a Cys837 residue of PLD1 and inhibited enzymatic activity of PLD. CAPE also decreased activation of matrix metalloproteinases-2 induced by phosphatidic acid, a product of PLD activity. Ultimately, CAPE-induced downregulation of PLD1 suppressed invasion and proliferation of glioma cells. Taken together, the results of this study indicate that CAPE might contribute to anti-neoplastic effect by targeting PLD1.
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Kim YJ, Lee DH, Kwon JY, Kang DW, Suh DC, Kim JS, Kwon SU. High resolution MRI difference between moyamoya disease and intracranial atherosclerosis. Eur J Neurol 2013; 20:1311-8. [PMID: 23789981 DOI: 10.1111/ene.12202] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 04/30/2013] [Indexed: 11/27/2022]
Abstract
BACKGROUND AND PURPOSE Along with intracranial atherosclerotic disease (ICAD), moyamoya disease (MMD) is the most common cause of middle cerebral artery (MCA) occlusion in Asians. Although they have differing vascular wall pathologies, conventional angiographic evaluation methods cannot easily differentiate MMD from ICAD in certain situations, such as in young patients with atherosclerotic risk factors. High resolution magnetic resonance imaging (HR-MRI) findings for the diseased segments of MCAs in MMD and symptomatic ICAD were compared to further elucidate differences in arterial wall changes. METHODS Angiographically confirmed patients, 12 MMD and 20 ICAD, who suffered a stroke due to MCA occlusion were recruited and underwent HR-MRI. The size of the outer diameter and other stenotic vessel wall characteristics revealed by HR-MRI, including enhancement, eccentricity and other lesion patterns, were analyzed by two independent reviewers in a blind fashion. RESULTS MMD patients were younger than ICAD patients (32.92 ± 11.08 years vs. 51.85 ± 11.97 years; mean ± SD) and displayed a smaller outer diameter in the stenotic portion (1.61 ± 0.43 mm for MMD vs. 3.03 ± 0.53 mm for ICAD, P < 0.0001). Eccentric lesions (three of 12 in MMD vs. 19 of 20 in ICAD, P < 0.0001) and focal enhancements in diseased areas (two of seven in MMD vs. 13 of 17 in ICAD, P = 0.061) were less common in MMD cases. CONCLUSIONS Our HR-MRI findings show that MMD is associated with smaller, concentric occlusive lesions which are rarely enhanced compared with symptomatic ICAD, consistent with the results of previous pathological reports. HR-MRI may therefore have utility in differentiating MMD from ICAD.
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